This image and text was taken from the Canon white paper on the 5D:
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The anti-aliasing filter, which also functions as the CMOS sensor package’s cover glass, consists of an infrared-blocking filter, a primary low-pass filter, a phase plate and a secondary low-pass filter. While other cameras, such as the EOS 20D camera, have three crystal plates, the EOS 5D model’s filter has one independent crystal plate doing double duty as the cover glass. This reduces cost without affecting the filter’s performance.
I believe that the dichroic mirror shown on the top layer of the sensor assembly is the TI coating.
